Various forms of sheet metal panels and doors have been heretofore provided with peripheral, crossed and diagonal bracing. However, most sheet metal doors or panels provided with such bracing are either constructed of multiple sheet metal sections or include only minimal bracing. Accordingly, a need exists for a one-piece sheet metal door or panel including ample peripheral bracing.
Examples of various forms of single and multiple sheet metal section panels and doors including peripheral and crossed bracing are disclosed in U.S. Pat. Nos. 1,768,742, 2,149,882, 2,241,266, 3,792,522 and 3,848,324.